Hurricane Irma: How dangerous is the devastating storm?

Hurricane Irma has caused a trail of destruction across parts of the Caribbean, battering a number of islands and reducing buildings to rubble.

The category five hurricane, which is the highest possible level for such a storm, is predicted to head north-west towards the US mainland by the weekend, but what lies in its path before that?

Irma is making headlines as the most powerful Atlantic storm in a decade with wind speeds of up to 295km/h (185mph).

The storm struck the dual-island nation of Antigua and the small island of Barbuda - which was later said to be "barely habitable" - and the French territories of Saint-Martin and Saint Barthélemy, popularly known as St Barts.

At least eight people were later reported killed in Saint-Martin and Saint Barthélemy. A further death was reported on Anguilla and a child was reported to have died on Barbuda.

With the scale of the damage still emerging the death toll is likely to rise.

On Thursday, the storm was progressing north of the Dominican Republic, heading towards Turks and Caicos.

The low-lying Turks and Caicos islands are said to be at risk of a storm surge, with the possibility of destructive waves up to 6m (20ft) higher than usual.

If Irma makes landfall in the US - as Hurricane Harvey did earlier - then it will be the first time that two storms measuring category four or above have done so during the same season since records began.

A state of emergency had been declared for Florida, Puerto Rico and the US Virgin Islands, mobilising US federal disaster relief efforts.

The storm is moving relatively slowly, at about 26km/h, as it heads towards the southern US coast from the Atlantic, past the Dominican Republic and the Bahamas.

The US National Hurricane Center said the storm's core was due to pass by the Dominican Republic coastline on Thursday.

The NHC has two types of warnings for this scenario: a hurricane warning ("preparations to protect life and property should be rushed"), a hurricane watch ("hurricane conditions are possible") and a tropical storm warning ("tropical storm conditions are expected somewhere within the warning area").

A caveat: forecasters projecting the direction of the storm warn that they could be wrong.

The projected path should not be seen as a guarantee of safety for those in nearby regions.

Irma is currently veering north-west, and is likely to skirt the north of Haiti on Friday, move over or near Cuba on Saturday and Sunday, possibly striking islands off Florida.

The projection for Sunday is that it will reach mainland Florida but again, that forecast is far from certain, and we do not know how powerful the storm will be by then.

Nonetheless, Florida's governor is warning the population not to take risks, warning that it is stronger than Hurricane Andrew (August 1992), which killed 65 people.

Officials have started evacuating tourists and residents of Florida Keys, a resort archipelago.

Flights to and from several airports in Florida have been suspended, while Orlando's international airport reporting that commercial flights would stop from 17:00 local time on Saturday.

The small island of Barbuda is said to be "barely habitable" while officials warn that the island of Saint Martin - divided between the French territory of Saint-Martin and Sint-Maarten, an independent nation within the Kingdom of the Netherlands, is almost destroyed.

Antigua and Barbuda Prime Minister Gaston Browne said about 95% of the buildings on Barbuda had suffered some damage.

Most of those reported killed were on Saint-Martin and Saint Barthélemy.

The airport in Sint-Maarten, the third largest in the Caribbean, has been severely damaged, with local officials saying that most buildings on the island have been levelled.

More than half of Puerto Rico's three million residents were without power as Irma caused heavy downpours and strong winds. Officials have said that power could be cut off for several days.

Hurricane Irma has been getting progressively stronger. On 4 September, it was a category three storm with winds of 195km/h. The next day, it was a category four, with speeds of 220km/h, and it's now at 295km/h.

The latest forecast predicts that the storm's power will fluctuate but is not clear how things will progress.

Flights between many of the islands, which include the Dominican Republic, Guadeloupe and the British Virgin Islands, have been cancelled. Antigua's airport was closed on Wednesday.

British Airways cancelled some flights, and sent an empty aircraft to Antigua to bring 326 travellers home early.

Airlines serving the three main airports in south Florida are reported to have cancelled or delayed several flights on Wednesday at Fort Lauderdale, Miami and Palm Beach International Airport,

Other airports in the state were advising passengers to check flight status with their airlines.

There are two other storms of concern at the moment - Hurricanes Jose and Katia. Storms are named in alphabetical order as they happen, so after Irma come names beginning with J and K.

Jose, further out in the Atlantic behind Irma, has swelled to category one hurricane strength and could be near major hurricane strength on Friday, according to the NHC.

Although its path is not clear, Jose could hit some areas already affected by Irma.

And Katia, in the Gulf of Mexico, was also recently upgraded to hurricane status, with warnings that it could hit the coast of the Mexican state of Veracruz.

Seeing multiple storms developing in the same area of the Atlantic in close succession is not uncommon.

Rarer though is the strength of the hurricanes, with Harvey - which recently hit Texas - making landfall as a category four.

All the signs are that official forecasters were not exaggerating when they described Hurricane Irma as "extremely dangerous" and "potentially catastrophic".

The threat to humans and property is unpredictable - we will not know the full extent of the fallout until later.

Hurricane Wilma, in 2005, had similar wind speeds and killed 87 people, costing billions in damage. But wind speeds are not always a good indicator of the damage a storm can do.

In 2016, Hurricane Matthew, which was less powerful, killed almost 600 people - more than 500 in Haiti. The NHC's final report said that poorly constructed homes were "completely destroyed" by winds.

Irma is currently only being beaten by 1980's Hurricane Allen for the strongest and most sustained wind speeds. As it intensified across the Caribbean it killed six people on St Lucia and 238 in the Antilles islands.

Hurricane Allen then reached a staggering 305km/h (190 mph) at its peak before hitting Texas with 205km/h (125mph) winds.

Fortunately it made landfall in a sparsely populated area of the US state, with few casualties recorded.

Extreme weather patterns are complex, and where the storm hits and how prepared the populace are may have a significant effect.

Local governments in the path of the storm are issuing their own instructions, which should be followed.

Ideally, those in the storm's path should have an emergency kit prepared in advance, with food, water, batteries, artificial light and other supplies.